Rolling door



Jam. M, W50 R. H. GREEGOR ROLLING DOOR 2 Sheets-Sheet 1 Filed March 21,1946 INVENTQW H. GREEGOW Zia/M RALPH ATTURWEWS Patented Jan. 31, 1950ROLLING DOOR Ralph H. Greegor, Columbus, Ohio, assignor to The KinnearManufacturing 00.,

Columbus,

Ohio, a corporation of Ohio Application March 21, 1946, Serial No.656,075

2 Claims. (01. 160-235) The present invention relates to metal curtainsof the slot type used for rolling overhead doors in large buildings,hangars, garages, etc.

The slat form of rolling door usually comprises a recurring series ofsheet metal plates, suitably interlocked or hinged at their longitudinaledges and adapted to roll over manual or power driven drums in order toraise or lower the door. While doors of this character are satisfactory,it has been found that in the case of a door of considerable width, thewind pressure may be so severe as actually to cause a bending effect.This may introduce permanent deformation of the slat or at least strainat the interlocking edges which interferes with the vertical movement ofthe curtain.

The primary object of the invention is to provide an improved door ofthe slat type which is strengthened widthwise to withstand transversestress and yet permitting the door to be rolled upwardly in the usualmanner.

Another object is to provide a rolling door of the slat interlockingtype with reenforcing elements extending over one or more slats tostrengthen the general construction of the door while still permittingthe door to coil about an overhead drum or to be received by any otheroverhead operating mechanism.

These objects are attained in brief by providing slats of rounded shapewhich terminate in loops which serve as hinges to give ease ofarticulation in coiling. The opposite loops of one slat are respectivelyreceived by the edge loops of the adjacent slats. Rigid plates having ashape conforming to the shape of the curved slats are secured theretoand preferably extend in the vertical direction across the interlockingloops of at least two adjacent slats. The effect of these rigid platesis to form wide slats with a higher crown than the original slats. Themember so produced is in efiect a beam of substantial cross sectionaldimensions and therefore is much stiffer than the slats were originally.The invention will be better understood when reference is made to thefollowing description and the accompanying drawings, in which:

Figure 1 represents a vertical sectional view of a building wall with anopening therein which is closed by a curtain of the slat type;

Figure 2 is a vertical sectional View of a portion of a curtain,improved in accordance with the present invention;

Figure 3 is a view similar to Figure 2 but showing the application ofthe reenforcing plates to a larger number of slats than in Figure 2;

Figure 4 is a perspective view of a reenforcing plate of a typicallength and as shown is adapted to be secured to two adjacent slats;while Figure 5 is an enlarged perspective view of a portion of animproved rolling door to which the reenforcing plates or strips havebeen applied.

Referring more particularly to Figures 1, 2 and 4, reference character Irepresents a vertical wall of a building having an opening 2 and inwhich the last course of bricks 3 are supported by a heavy I-beam 4. Arelatively large curvilinear casing 5 is supported on the wall I in anywellknown and suitable manner, this casing containing a manual or powerdriven drum for coiling a metal curtain thereon, generally designated at6. It will be understood that instead of causing the curtain 6 to wrapitself about a coiling mechanism contained in the casing 5, the curtainmay be caused to roll over a curved surface within the casing 5 anddrawn along a horizontal top support which in the case of a garage mayconstitute the underside of the second story floor.

An enlarged view of a portion of the improved curtain 6 is shown in Fig.2. As illustrated, the curtain may comprise a plurality of slats madepreferably of steel, aluminum or copper and out of sheet metal. Eachslat is preferably provided with a relatively wide curved portion,indicated at l, and a narrow curved portion, indicated at 8, reverselyarranged. These curved portions terminate in oppositely directed loops9, it. Thus, each slat section is provided with reverse curves whichconstitute a good watershed since the outermost portions of the convexsurfaces tend to protect the inwardly projecting or concave portions ofeach slat. The curved sections are so designed as to distribute metal onboth sides of the vertical axis sufficiently equal to provide the samehorizontal resistance to forces from either side. The particular effectof this section permits the slat to slightly open up or flatten whenresisting horizontal forces and this effect allows additionalresiliency, providing a strong but flexible curtain with slats that aredifficult to cripple.

The loop 9 is made preferably of smaller diametralsize than the loop Inin order that the latter may slidably receive the smaller loop of thelower adjacent slat. The metal at each of the loops continues in thecircular direction a suflicient distance to cause the loops to interlockin the vertical direction of the curtain. It is apparent that these slatportions of the curtain are assembled by sliding endwise the loop end ofone 3 slat into the loop of the adjacent slat. These slats are usuallyfairly narrow, perhaps on the order of 2 or less so that the rigidity ofeach slat does not materially interfere with the facility with which thecurtain is caused to coil about the overhead drum.

Curtains of this general type have been found to be satisfactory inoperation but when the curtain is of considerable width, for example, inthe case of a hangar door located in an exposed posi tion, it has beenfound that in the case of extremely heavy wind, the resulting pressuresare so great as to cause strains at the interlocking loops and inextreme cases, the curtain may bend or buckle at the middle. Inaccordance with the present invention, I provide a number of rigidplates or strips of metal preferably shaped equidistantly apart acrossthe entire widthof the curtain and extendin over one or more loop jointsto serve as a reenforcement. In Fig. 2, the reenforcing plate isindicated at It and has a configuration which closely approximates theshape of the reverse curved slats except that a relatively straightportion [2 is provided directly opposite the loops 9, it. The length ofeach plate as measured in the vertical direction will depend on thewidth of the slats and in case it is desired that the length of theplate shall be limited to the span of two slats, the plate willpreferably terminate at a position where the loops 9, iii

begin. The width of each strip, as measured horizontally of the curtain,will depend on the amount of reenforcement necessary and also on thewidth of the curtain which determines the number of plates applied perfoot of width of the curtain. For a curtain of typical size and exposedto average wind conditions, plates of approximately 4" width and spacedapproximately 1 /2 feet apart over the entire width of the curtain willbe found to give satisfactory results.

The plates I! may be made of sheet steel and have considerably greaterthickness than the thickness of the slats. They are secured to the slatsin any suitable manner such as by-spotwelding but preferably by the useof fiat-headed rivets, indicated at iii. For this purpose, the platesare initially provided with holes M "and these holes are so positionedthat they come within the relatively flat portion of the plates whichlends ease pf drilling openings in the relatively flat portions of theslats. A perspective view of a double-slat portion of the improvedcurtain which has in effect been formed into a'ri'gid single slat by theuse of the plates H is shown Figure 5. The over-all width of thedouble-unit slat is still sufficiently small as not to interfere greatlywith the coiling effect on the overhead drum. When a curtain has beenprovided with the plates H, as described hereinbefore. it has been foundthat the strengthening or reenfo'rcing effect offered by these plates inthe widthwise direction is phenomenally great so that the curtain offersa strong resistance to any horizontal force, particularly at the middleof a wide curtain and without reducing in any appreciable degree thebendability of the curtain at the overhead elevating mechanism.

The combined slat sections can be so assembled in a curtain, that thecurtain is made up entirely of these sections, or these built-upsections can be used intermittently to reenforce a rolling door. Thisincreased crown effect can be readily 'discerned from the showing inFigure 2 in which the intermediate joints 9 and Ill have been movedconsiderably away from the line connecting the uppermost joint 9 and thelowermost joint 10 so that the crown in a given size and shape of doormay be approximately 1%" instead of which it would have been without theplates 12. This could be increased or decreased as desired. Thus, thesections formed of two or more slats which are joined together by theplates 42 are provided with a larger. moment of inertia and therebyoffer increased resistance to deflection.

In an extreme case as when unusual reenforcement becomes necessary, theplates I! may be of such length as to embrace three adjacent slats oreven more when desired. A portion of a curtain which has beenconstructed in this man ner is shown in Figure 3 and it will be notedthat the plate H has greater length than in the case of Figure 2 so asto terminate at the loop portions 9, IQ of each group of three slats.While it is apparent that the relatively long plate II will serve toreduce the cendability of the curtain shown in Figure 3 greater than inthe case of that illustrated in Figure 2, nevertheless a certain anduseful amount of articulation is retained at the upper and lower freeloops which will still permit the curtain to coil about a drum. In theevent that the curtain is elevated to its full open position whileremaining in avertical direction, it is' apparent thatthe rigid plate llmay extend over as many slats as desired in order to increase thereenforcing effect which opposes transverse stresses caused by gusts ofwind, etc.

From the foregoing, it is evident that I have disclosed an improved formof a rolling slat cur-' tain which can be readily and inexpensivelyreenforced against strong transverse pressures com-- ing from one sideor the opposite side of the curtain while retaining the curved slatconstruction which offers unusual benefits from the standpoint ofwatershed. The slats, at the point of articula tion aresecurelyinterlocked in the vertical direction sothat even in the case ofcurtains of considerable height each slat remains securely in positionwithout interfering with the articulation function. 4

It will be understood that various modifications and arrangements instructure could be made without departing from the spirit of my inven'tion and, accordingly, I desire to comprehend such modifications andsubstitutions of equiva lents as may be considered to come within thescope of the appended claims.

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent is: l

1. .An articulated metal curtain formed of crowned metal slatsterminating at the edges in loop portions, the loops of one slat beingadapted to respectively engage the loops the adjacent slats to formslidable joints. and. a plurality of rigid reenforcing plates extendingacross at least two of the adjacent slats as far as the oppositelydisposed loops of the double-slat unit in order to fix the two slatsrigidly with respect to one another at an angle which substantiallyincreases the crown thereof to impact resistance to the curtain withrespect to transverse width pressure, said plates being spaced along thelengths of said slats.

2. A curtain formed of metal slats having a reversed curvedconfiguration widthwise of each slat and terminating along each edge ina substantially complete loop portion, the loop portions of each slatbeing adapted slidably to be re-' ceived by the'loop portions of theadjacent slats to form articulated joints between the slats, andREFERENCES CITED a reenforcing metal strip having the same con- Th f n If n f d th figuration lengthwise as the Widthwise configufile i fi ere088 are 0 recor m e ration of the adjacent slats secured to said slats pin order to strengthen the curtain as a whole 5 UNITED STATES PATENTSagainst external forces applied to the middle of N 1 the curtain, saidstrips being formed to hold said gg b i' b slats convex outwardly of thecurtain to provide 1 367240 1921 a summing beam efiect- 114371947Probert Dec. 5, 1922 1,579,915 Cornell Apr. 6, 1926 RALPH H-GREEGOR'2,204,363 Jenkins June 11,1940

